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Hill SJ, Young A, Prendergast B, Redwood S, Rajani R, De Vecchi A. Patient-specific fluid simulation of transcatheter mitral valve replacement in mitral annulus calcification. Front Cardiovasc Med 2022; 9:934305. [PMID: 36588546 PMCID: PMC9797989 DOI: 10.3389/fcvm.2022.934305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
Introduction Transcatheter mitral valve replacement is a promising alternative to open-heart surgery in elderly patients. Patients with severe mitral annulus calcification (MAC) are a particularly high-risk population, where postprocedural complications can have catastrophic effects. Amongst these, obstruction of the left ventricular outflow tract can lead to ventricular hypertrophic remodeling and subsequent heart failure, while subclinical valve thrombosis can result in early bioprosthetic valve failure. Methods To elucidate the mechanisms of left ventricular outflow tract obstruction and valve thrombosis following valve-in-MAC procedures, we used image processing and Computational Fluid Dynamics (CFD) software to generate patient- and device-specific models based on preprocedural CT data. Personalized computer simulations were performed to predict the left ventricular haemodynamics after implantation in three patients with severe MAC. Results The simulations have successfully captured the increased pressure gradient in the left ventricular outflow tract as a result of the partial obstruction due to the implanted valve. Regions of wall shear stress above the threshold value for platelet activation were also observed on the bioprosthetic frame as a result of the reduced outflow tract area, which led to increases in flow resistance and blood residence time inside the ventricle. Consistent with these findings, areas of slow recirculating flow and blood stasis formed near the valve frame, creating potential pro-thrombotic conditions. Discussion This study provides insight into the relationship between size and shape of the outflow tract post-implantation, pressure gradients and pro-thrombotic flow metrics such as wall shear stress and blood residence time. Results show the potential of CFD modeling to bring key functional metrics into preprocedural assessment for a comprehensive evaluation of post-procedural risks beyond anatomical factors. Following further validation and extension to the atrial chamber, this approach can provide an in-depth analysis of the likelihood of valvular thrombosis.
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Affiliation(s)
- Samuel Joseph Hill
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Alistair Young
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Bernard Prendergast
- Cardiovascular Directorate, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Simon Redwood
- Cardiovascular Directorate, Guy’s and St Thomas’ NHS Foundation Trust, London, United Kingdom
| | - Ronak Rajani
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
| | - Adelaide De Vecchi
- School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom
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Grafton-Clarke C, Njoku P, Aben JP, Ledoux L, Zhong L, Westenberg J, Swift A, Archer G, Wild J, Hose R, Flather M, Vassiliou VS, Garg P. Validation of aortic valve pressure gradient quantification using semi-automated 4D flow CMR pipeline. BMC Res Notes 2022; 15:151. [PMID: 35488286 PMCID: PMC9052497 DOI: 10.1186/s13104-022-06033-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 04/11/2022] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE Doppler echocardiographic aortic valve peak velocity and peak pressure gradient assessment across the aortic valve (AV) is the mainstay for diagnosing aortic stenosis. Four-dimensional flow cardiovascular magnetic resonance (4D flow CMR) is emerging as a valuable diagnostic tool for estimating the peak pressure drop across the aortic valve, but assessment remains cumbersome. We aimed to validate a novel semi-automated pipeline 4D flow CMR method of assessing peak aortic value pressure gradient (AVPG) using the commercially available software solution, CAAS MR Solutions, against invasive angiographic methods. RESULTS We enrolled 11 patients with severe AS on echocardiography from the EurValve programme. All patients had pre-intervention doppler echocardiography, invasive cardiac catheterisation with peak pressure drop assessment across the AV and 4D flow CMR. The peak AVPG was 51.9 ± 35.2 mmHg using the invasive pressure drop method and 52.2 ± 29.2 mmHg for the 4D flow CMR method (semi-automated pipeline), with good correlation between the two methods (r = 0.70, p = 0.017). Assessment of AVPG by 4D flow CMR using the novel semi-automated pipeline method shows excellent agreement to invasive assessment when compared to doppler-based methods and advocate for its use as complementary to echocardiography.
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Affiliation(s)
| | - Paul Njoku
- Norwich Medical School, University of East Anglia, Norwich, S10 2RX UK
| | | | - Leon Ledoux
- Pie Medical Imaging, Maastricht, The Netherlands
| | | | - Jos Westenberg
- Leids Universitair Medisch Centrum, Leiden, The Netherlands
| | | | | | | | - Rod Hose
- University of Sheffield, Sheffield, UK
| | - Marcus Flather
- Norwich Medical School, University of East Anglia, Norwich, S10 2RX UK
| | | | - Pankaj Garg
- Norwich Medical School, University of East Anglia, Norwich, S10 2RX UK
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Franke B, Brüning J, Yevtushenko P, Dreger H, Brand A, Juri B, Unbehaun A, Kempfert J, Sündermann S, Lembcke A, Solowjowa N, Kelle S, Falk V, Kuehne T, Goubergrits L, Schafstedde M. Computed Tomography-Based Assessment of Transvalvular Pressure Gradient in Aortic Stenosis. Front Cardiovasc Med 2021; 8:706628. [PMID: 34568450 PMCID: PMC8457381 DOI: 10.3389/fcvm.2021.706628] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 07/09/2021] [Indexed: 01/07/2023] Open
Abstract
Background: In patients with aortic stenosis, computed tomography (CT) provides important information about cardiovascular anatomy for treatment planning but is limited in determining relevant hemodynamic parameters such as the transvalvular pressure gradient (TPG). Purpose: In the present study, we aimed to validate a reduced-order model method for assessing TPG in aortic stenosis using CT data. Methods: TPGCT was calculated using a reduced-order model requiring the patient-specific peak-systolic aortic flow rate (Q) and the aortic valve area (AVA). AVA was determined by segmentation of the aortic valve leaflets, whereas Q was quantified based on volumetric assessment of the left ventricle. For validation, invasively measured TPGcatheter was calculated from pressure measurements in the left ventricle and the ascending aorta. Altogether, 84 data sets of patients with aortic stenosis were used to compare TPGCT against TPGcatheter. Results: TPGcatheter and TPGCT were 50.6 ± 28.0 and 48.0 ± 26 mmHg, respectively (p = 0.56). A Bland–Altman analysis revealed good agreement between both methods with a mean difference in TPG of 2.6 mmHg and a standard deviation of 19.3 mmHg. Both methods showed good correlation with r = 0.72 (p < 0.001). Conclusions: The presented CT-based method allows assessment of TPG in patients with aortic stenosis, extending the current capabilities of cardiac CT for diagnosis and treatment planning.
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Affiliation(s)
- Benedikt Franke
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Jan Brüning
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Pavlo Yevtushenko
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Henryk Dreger
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Cardiology and Angiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Anna Brand
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Cardiology and Angiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Benjamin Juri
- Department of Cardiology and Angiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Axel Unbehaun
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Jörg Kempfert
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Simon Sündermann
- Department of Cardiology and Angiology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Alexander Lembcke
- Department of Radiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Natalia Solowjowa
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Sebastian Kelle
- Department of Cardiology, German Heart Center Berlin, Berlin, Germany
| | - Volkmar Falk
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Titus Kuehne
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Congenital Heart Disease, German Heart Center Berlin, Berlin, Germany
| | - Leonid Goubergrits
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Einstein Center Digital Future, Berlin, Germany
| | - Marie Schafstedde
- Institute of Computer-assisted Cardiovascular Medicine, Charité - Universitätsmedizin Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Congenital Heart Disease, German Heart Center Berlin, Berlin, Germany.,Berlin Institute of Health (BIH), Charité - Universitätsmedizin Berlin, Berlin, Germany
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Validation of four-dimensional flow cardiovascular magnetic resonance for aortic stenosis assessment. Sci Rep 2020; 10:10569. [PMID: 32601326 PMCID: PMC7324609 DOI: 10.1038/s41598-020-66659-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 05/18/2020] [Indexed: 11/18/2022] Open
Abstract
The management of patients with aortic stenosis (AS) crucially depends on accurate diagnosis. The main aim of this study were to validate the four-dimensional flow (4D flow) cardiovascular magnetic resonance (CMR) methods for AS assessment. Eighteen patients with clinically severe AS were recruited. All patients had pre-valve intervention 6MWT, echocardiography and CMR with 4D flow. Of these, ten patients had a surgical valve replacement, and eight patients had successful transcatheter aortic valve implantation (TAVI). TAVI patients had invasive pressure gradient assessments. A repeat assessment was performed at 3–4 months to assess the remodelling response. The peak pressure gradient by 4D flow was comparable to an invasive pressure gradient (54 ± 26 mmHG vs 50 ± 34 mmHg, P = 0.67). However, Doppler yielded significantly higher pressure gradient compared to invasive assessment (61 ± 32 mmHG vs 50 ± 34 mmHg, P = 0.0002). 6MWT was associated with 4D flow CMR derived pressure gradient (r = −0.45, P = 0.01) and EOA (r = 0.54, P < 0.01) but only with Doppler EOA (r = 0.45, P = 0.01). Left ventricular mass regression was better associated with 4D flow derived pressure gradient change (r = 0.64, P = 0.04). 4D flow CMR offers an alternative method for non-invasive assessment of AS. In addition, 4D flow derived valve metrics have a superior association to prognostically relevant 6MWT and LV mass regression than echocardiography.
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Yaari D, Rubinshtein R, Sachner R, Gaspar T, Adawi S, Jaffe R, Asmer I, Ganaeem M, Shiran A. The effect of aortic area measurement site on the energy loss coefficient: a comparison between echocardiography and cardiac computed tomography angiography in patients with aortic stenosis. Echocardiography 2016; 33:1649-1655. [DOI: 10.1111/echo.13331] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Dotan Yaari
- Ruth and Bruce Rappaport Faculty of Medicine; Technion-Israel Institute of Technology; Haifa Israel
| | - Ronen Rubinshtein
- Ruth and Bruce Rappaport Faculty of Medicine; Technion-Israel Institute of Technology; Haifa Israel
- Department of Cardiovascular Medicine; Lady Davis Carmel Medical Center; Haifa Israel
| | - Robert Sachner
- Department of Radiology; Lady Davis Carmel Medical Center; Haifa Israel
| | - Tamar Gaspar
- Ruth and Bruce Rappaport Faculty of Medicine; Technion-Israel Institute of Technology; Haifa Israel
- Department of Radiology; Lady Davis Carmel Medical Center; Haifa Israel
| | - Salim Adawi
- Ruth and Bruce Rappaport Faculty of Medicine; Technion-Israel Institute of Technology; Haifa Israel
- Department of Cardiovascular Medicine; Lady Davis Carmel Medical Center; Haifa Israel
| | - Ronen Jaffe
- Ruth and Bruce Rappaport Faculty of Medicine; Technion-Israel Institute of Technology; Haifa Israel
- Department of Cardiovascular Medicine; Lady Davis Carmel Medical Center; Haifa Israel
| | - Ihab Asmer
- Department of Cardiovascular Medicine; Lady Davis Carmel Medical Center; Haifa Israel
| | - Majdi Ganaeem
- Department of Cardiovascular Medicine; Lady Davis Carmel Medical Center; Haifa Israel
| | - Avinoam Shiran
- Ruth and Bruce Rappaport Faculty of Medicine; Technion-Israel Institute of Technology; Haifa Israel
- Department of Cardiovascular Medicine; Lady Davis Carmel Medical Center; Haifa Israel
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